Svg doesn't have support for images that do not define a width of height.
If you try to apply an image style on an svg without width or height, you get a divide by zero error.
Also, svg doesn't support width or height in other formats then 'px'. It thinks that all the values are in px.

What will have to change?

  1. Database columns will have to be changed away from int to something string like to support 'x px' or 'x cm'
  2. The image styles will have to be able to cope with 'cm' etc..

To check out

  1. Does Drupal image module support 'cm' for images?
  2. How does Drupal image module store width and hight?